Field of the Invention
The present invention relates to a substrate processing apparatus comprising a plurality of heating modules each including a table on which a substrate is placed to be heated, and a method of adjusting the substrate processing apparatus.
Background Art
In a semiconductor manufacturing process, a coating film is formed on a substrate such as a semiconductor wafer (referred to as “wafer” below), and then the substrate is placed on a table provided therein with a heater so as to be subjected to a heating process. The heating process may be a process in which a resist film formed on a substrate is heated at a temperature of about, e.g., 100° C. before and after exposure. The line width of a resist pattern varies depending on various factors. One of such factors is a heating temperature during the heating process.
Since solubility of resists to developers is more likely to depend on the resist temperature histories in these days, the temperature history differences between portions of one wafer and between wafers have greater influences on in-plane uniformity and inter-wafer uniformity of the line width of resist pattern.
A heating module that performs a heating process by using a plurality of heaters each assigned to respective ones of heated zones (which are defined by dividing the surface of one wafer into a plurality of zones). Heat generation of the heaters is controlled independently from each other. A known method of controlling parameters of a heater control system as described in Japanese Patent No. JP4391518B measures temperatures of a table (heating plate) at a plurality of measurement points, and controls heaters such that the measured temperatures correspond to respective target temperatures. However, in order to cope with a process that requires stricter line width uniformity, improvement of the control method will be required.
A resist-pattern forming apparatus includes a plurality of heating modules in order to process a plurality of wafers at the same time. Therefore, not only the in-plane temperature-history uniformity in each wafer, but also the inter-plane temperature-history uniformity of wafers processed by different heating modules is required.